Resonant tunneling and Fano resonance in quantum dots with electron-phonon interaction

Abstract

We theoretically study the resonant tunneling and Fano resonance in quantum dots with electron-phonon (e-ph) interaction. We examine the bias-voltage ($V$) dependence of the decoherence, using Keldysh Green function method and perturbation with respect to the e-ph interaction. With optical phonons of energy ${\omega }_0$, only the elastic process takes place when $eV<{\omega }_0$, in which electrons emit and absorb phonons virtually. The process suppresses the resonant amplitude. When $eV>{\omega }_0$, the inelastic process is possible which is accompanied by real emission of phonons. It results in the dephasing and broadens the resonant width. The bias-voltage dependence of the decoherence cannot be obtained by the canonical transformation method to consider the e-ph interaction if its effect on the tunnel coupling is neglected. With acoustic phonons, the asymmetric shape of the Fano resonance grows like a symmetric one as the bias voltage increases, in qualitative accordance with experimental results.

28 pages, 11 figures

References in corpus (1)

• Dephasing in sequential tunneling through a double-dot interferometer

Cited by in corpus (5)

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• Fano effect in a Josephson junction with a quantum dot
• Suppressed conductance in a metallic graphene nano-junction
• Quantum transport in a resonant tunnel junction coupled to a nanomechanical oscillator
• Transport through a multiply connected interacting meso-system using the Keldysh formalism